Method for assembling a vehicle

ABSTRACT

An engine mount for a vehicle, such as a snowmobile, that can be used when space for the engine within a chassis is limited and which is easily accessed from the side of the chassis for assembly and repair. The engine mount can be attached to the bottom of an engine that is positioned within a chassis. The engine mount can include four hollow, cylindrical portions. Each cylindrical portion having an axis extending transverse to the longitudinal direction of the snowmobile chassis and receiving a damping mount. Fasteners can be inserted through the chassis to couple with the damping mounts and cylindrical portions in a direction that is transverse to the longitudinal direction of the chassis. The configuration of the damping mounts permits effective damping especially in a direction transverse to the direction of forward travel of the vehicle.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Divisional of U.S. application Ser. No. 09/877,211 filed onJun. 11, 2001, the contents of which are incorporated herein byreference. This application claims the benefit of priority to U.S.Patent Application No. 60/245,675, filed Nov. 6, 2000, the contents ofwhich are herein incorporated by reference. This application is alsorelated to U.S. patent application Ser. No. 09/472,134 for a SNOWMOBILE,filed Dec. 23, 1999; to U.S. Patent Application No. 60/167,614 for aSNOWMOBILE, filed Nov. 26, 1999; and U.S. Patent Application No.60/230,432 for a NOVEL THREE WHEEL VEHICLE, filed Sep. 6, 2000, thecontents of each being incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to supporting elements within avehicle. More specifically, the invention relates to a support for avehicle engine.

2. Background of the Invention

Typically, a snowmobile is powered by a two-stroke engine, which cancause large amounts of vibration. In order to decrease the amount ofvibration from the engine to the chassis, typically, such engines weresupported by an engine mount attached to the bottom of the engine in away that enabled bolts with position-adjustable dampers to be placedbetween the engine mount and the chassis. However, such conventionalengine mounts required relatively large amounts of space within thechassis for the engine and to provide the space needed to position theadjustable dampers. Also, conventional engine mounts require more spacein the chassis at the front and rear of the engine. Further, previousengine mount dampers were designed to work most effectively againstmovement of the engine in the direction of movement of the vehicle andin the direction of the height of the vehicle, which in some situationsis not the preferred direction for accommodating and damping forces suchmovements generate.

Accordingly, there exists a need for a new engine mount that can be usedin a vehicle, such as a snowmobile, where the chassis has less availablespace for both the engine and for such an new engine mount. There isalso a need for an engine mount that can be more easily assembled andaccessed during production and repair activities and that caneffectively reduce movement in a direction lateral to the direction oftravel.

SUMMARY OF THE INVENTION

An object of the invention is to provide an improved engine mount for avehicle.

Another object of the invention is to provide a snowmobile having anengine mount that can be used when space is limited within a chassis forthe engine and engine mount.

Yet another object of the invention is to provide an improved resilient,damping mount for an engine.

Yet a further object of the invention is to provide an engine mount fora vehicle that can be installed and access from the sides of the vehicleto simplify production on an assembly line.

These and other objects of the invention may be accomplished byproviding a base plate for securing an engine to a chassis. The baseplate can include a body portion for securing to the bottom of theengine and at least a pair of cylinders extending from the body portion.The cylinders can receive fasteners and damping members for securing theengine to the chassis in a secure, damped manner.

These and other objects of the invention may be further accomplished byproviding a mounting element for mounting an engine to a chassis. Themounting element can include a threaded socket having a first flange, ashoulder washer having a second flange and a resilient materialpositioned between and coupled to the first and second flanges toprovide a resilient connection between the chassis and the engine.

These and other objects of the invention may be further accomplished byproviding a vehicle having a chassis and an engine secured to thechassis by an engine mount. The engine mount can have a base plate forsecuring an engine to a chassis. The base plate can include a bodyportion secured to the bottom of the engine and cylinders extending fromthe body portion. The cylinders can receive fasteners and dampingmembers for securing the engine to the chassis in a secure, dampedmanner. The damping members can include a threaded socket having a firstflange, a shoulder washer having a second flange and a resilientmaterial positioned between and coupled to the first and second flangesto provide a resilient connection between the chassis and the engine.

These and other objects of the invention may be further accomplished byproviding a method of assembling a vehicle that includes securing thebase plate to the engine, positioning the engine and the attached baseplate within in opening in the top of the chassis, and inserting afastener through the side of the chassis and into the threaded socket ofthe damping member.

Other objects, advantages, and features of the invention will becomeapparent to those skilled in the art from the follow detaileddescription which, taken in conjunction with the annexed drawings,discloses preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in the detailed descriptionwhich follows, by reference to the noted drawings by way of non-limitingexemplary embodiments, in which like reference numerals representsimilar parts throughout the several views of the drawings, and wherein:

FIG. 1 illustrates a left side view of an engine mount in accordancewith an embodiment of the invention attached to an engine and a chassisof a snowmobile;

FIG. 2 illustrates a front/left/top exploded, perspective view of theengine mount and engine of FIG. 1.;

FIG. 3 illustrates a top view of the engine mount of FIG. 1 secured tothe chassis;

FIG. 4 is a cross-section view of the engine mount and the chassis takenalong line 4—4 in FIG. 3;

FIG. 5 illustrates a left side, top, rear perspective view of thechassis of the snowmobile of FIGS. 1-4;

FIG. 6 shows the exterior of the left and interior of the right side ofthe chassis of FIG. 5 and its engine receiving area;

FIG. 7 shows a front, top view of the chassis of FIG. 5 and its enginereceiving area;

FIG. 8 shows the interior of the left side of the chassis of FIG. 5 andits engine receiving area;

FIG. 9 shows a top view of the engine mount of FIG. 1;

FIG. 9(a) shows a top view of another exemplary engine mount accordingto the invention;

FIG. 10 shows a bottom view of the engine mount of FIG. 1;

FIG. 10(a) shows a bottom view of the engine mount of FIG. 9(a);

FIG. 11 shows a rubber mount in accordance with an embodiment of thepresent invention;

FIG. 12 illustrates a cross-sectional view of the rubber mount shown inFIG. 11 along line 12—12, which is similar to the cross-section of therubber mount illustrated in FIG. 4;

FIG. 13 illustrates a cross-sectional view of a shoulder washer of therubber mount of FIG. 12 taken along line 12—12 of FIG. 11;

FIG. 14 illustrates a cross-sectional view of a threaded socket of therubber mount of FIG. 12 taken along line 12—12 of FIG. 11; and

FIG. 15 illustrates a front view the threaded socket of FIG. 14.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

As seen in FIGS. 1-4, a portion of a vehicle 10, such as a snowmobile,is illustrated, including a section of a chassis 12, an engine 14, andan engine mount 16 coupling the engine 14 to the chassis 12. The enginemount 16 both secures the engine 14 to the chassis 12 and dampsvibration generated by the engine 14. The goal is to have the amount ofvibration transferred from the engine 14 to the chassis 12 reduced toacceptable levels. The engine mount can include a base plate 20 anddamping mounts 22.

Although engine mount 16 is described herein with respect to asnowmobile, it should be understood that engine mount 16 can be usedwith other vehicles where engines are mounted, as well as withnon-vehicle equipment having an engine. Also, although engine mount 16is described as supporting an engine, the engine mount 16 can be used tosupport other devices other than engines, especially if there exists aneed to reduce vibration between the supported part and another partconnected thereto.

As seen in FIGS. 5-8, the snowmobile chassis 12 can include a tunnel 30and an engine cradle 34. The chassis also can include a pyramid-shapedupper support structure or “superframe” 32 positioned on top of thetunnel 30 and the engine cradle 34. The tunnel 30, engine cradle 34, andsuperframe 32 are described in more detail in U.S. Patent ApplicationNo. 60/230,432. The forward portion 31 of the chassis can include theengine cradle 34, into which engine 14 can be positioned and supported.The chassis 12 can have a longitudinal (X-) axis 52 oriented to extendin the direction of forward and rearward travel of the snowmobile 10 anda transverse (Y-) axis 54 oriented to extend substantiallyperpendicularly to the longitudinal axis 52 and transverse to thedirection of forward and rearward travel of the snowmobile 10.

The engine cradle 34 or apron can be of any appropriate construction andcan include an inclined-front wall 36, an inclined rear wall 38, and afloor 40 extending between front and rear walls 36 and 38. The enginecradle 34 can be enclosed on the left side by exterior support wall 42and on the right side by interior support wall 44. Exterior support wall42 can form part of the exterior side of the chassis and can includereinforcing panels for increased strength, if necessary. Interiorsupport wall 44 can extend within engine cradle 34 and between andrigidly attached to inclined front and rear walls 36 and 38,respectively. Exterior support wall 42 can have front and rear holes 46and 47, respectively, extending therethrough. Likewise, interior supportwall 44 can have front and rear holes 48 and 49, respectively, extendingtherethrough. Holes 4649 can receive fasteners, such as bolts 160, thatextend through the support walls 42 and 44 and into the engine mount 16for attaching the engine mount 16 to the chassis 12.

Engine 14 can be any of a variety of engine types. For example, engine14 can be a two-stroke engine, such as those used for powering somesnowmobiles or it can be a larger, more powerful engine for othervehicles. The illustrated engine 14 has a top 70, a bottom 72, a front74, a rear 76, and a crankshaft 77. Engine 14 can also have fasteners 78extending down from the bottom 72 for attachment with the engine mount16, as discussed below. For example, fasteners 78 can be threaded boltsor similar fasteners that protrude from the bottom of the engine 14,pass through the engine mount 16, and are fastened to the base plate 20by securing fasteners, such as threaded nuts 80. Of course, the engine14 can be adapted to receive fasteners as a female part rather than as amale part, as illustrated, or other forms of fasteners can also be used.

Engine 14, for example, can be oriented along the transverse axis 54.That is, the crankshaft 77 can be substantially parallel to thetransverse axis 54. The crankshaft 77 can be coupled to the driven shaft82 that drives the track 84 beneath the chassis 12, as described in thecommonly assigned applications mentioned above, which are incorporatedby reference, along with the commonly assigned U.S. Patent ApplicationNo. 60/236,739 for IN-LINE FOUR STROKE SNOWMOBILES, filed Oct. 2, 2000,the contents of which are herein incorporated by reference. Theconnection between crankshaft 77 and driven shaft 82 can, for example,be made by a driving pulley 86, a transmission, and a driven pulley 88by a belt 90. The belt can be oriented substantially parallel to thelongitudinal axis 52.

As seen in FIGS. 14, 9 and 10, base plate 20 has a middle or bodyportion 100, having a top 112 and a bottom 114, that has four hollowportions 101, 102, 103 and 104 provided at the corners-of the middle100. As shown in FIGS. 1-4, 9 and 10 the hollow portions 101, 102, 103and 104 are cylinders. It should be appreciated, however, that thehollow portions may be formed in other shapes, such as polygonal orcombinations of linear and curvilinear sides. The hollow portions 101,102, 103 and 104 are formed as cylinders as the engine mount is extrudedin a preferred embodiment and the cylindrical shape is more easilyextruded than, for example, polygonal shapes. It should also beappreciated that hollow portions 101 and 102 may be formed as a singlehollow portion and hollow portions 103 and 104 may be formed as a singlehollow portion. The preferred embodiment of the present inventionprovides two sets of coaxial hollow portions 101, 102 and 103, 104 toeliminate the material between the hollow portions and reduce weight.

Cylinders 101 and 102 have a common axis 106 that is substantiallyparallel to the transverse axis 54. Cylinders 103 and 104 can have acommon axis 108 that is likewise substantially parallel to thetransverse axis 54 but spaced from axis 106 and on the opposite side oftransverse axis 54 from axis 106. Base plate 20 can be and preferably isa unitary, one-piece integrally formed element made from any appropriatematerial. For example, base plate 20 can be formed from aluminum, steel,reinforced plastic material, other manmade materials, other metals, orcombinations thereof. Also, base plate 20 can be formed from a pluralityof structural elements that are appropriately connected, such as bywelding. The engine mount 16 can made from various materials andprocesses including an aluminum extrusion forming a unitary element orwelded from multiple parts made from other metals, including, forexample, steel.

The middle portion 100 can be shaped to conform to the bottom design ofengine 14 and can take any shape that permits the top surface of baseplate 20 to adequately attach to the element being supported, such asengine 14 or another element such as an intermediate member betweenengine 14 and base plate 20. The attachment between base plate 20 andengine 14 can take a variety of forms, including threaded bolt dependingfrom below the engine 14. Bolts 78 can extend through associatedopenings 110 provided in base plate 20. Openings 110 have been sized topermit fasteners 78 to extend completely therethrough and be secured bynuts on the bottom side 114 of base plate 100. Other fasteningtechniques, including bolts passing upwardly through base plate 20 andinto threaded holes in the engine block, could also be used.

As would be known to one skilled in the art, hollow portions 101, 102,103 and 104 could be separated such as shown in FIG.' 9(a). FIG. 9(a)illustrates hollow portions 101 and 103 attached to a separate middleportion 113 and hollow portions 102 and 104 attached to another middleportion 115. It would be appreciated also that hollow portion 101 and102 could be placed on a separate middle portion than 103 and 104 aswell as having all four hollow portions 101,102,103 and 104 eachindividually separated with it own separate base portion.

As best seen in FIGS. 1 and 11-15, each damping mount 22 can include athreaded socket 130, a shoulder washer 132, and a resilient member 134positioned therebetween. Although the mounting and connectionarrangement of each cylinder 101-104 does not necessarily have to beidentical to the other, base plate 20 is described herein as having foursubstantially identical damping mounts, with one damping mount 22attached to each cylinder 101-104. Consequently, only one will bedescribed in detail.

Threaded socket 130 has a flange 150 and an axial extension 152 that areconstruction as an integral, single element. Of course, socket 130 canbe formed from multiple elements. Socket 130 can be formed from metallicmaterial such as steel, aluminum, reinforced plastic material, othermanmade materials, other metals, or combinations thereof. Flange 150 ispreferably annular and has a substantial front surface area 154 that, inuse, faces the adjacent support wall 42 or 44. The surface area 154 canbe knurled on the face that contacts the adjacent support wall 42 or 44to prohibit rotation when attached. The axial extension 152 can besubstantially cylindrical with a threaded inner surface 156 capable ofbeing mated with a threaded fastener 160, as shown in FIG. 4, forsecuring the damping mount 22 to the chassis 12. The extension 152 alsocan be sufficiently long and narrow to extend within shoulder washer132.

Shoulder washer 132 has a flange 170 and an extension 172 and they arepreferably made as a single element. Of course, shoulder washer 132 canbe formed from multiple elements. Washer 132 can be formed of metallicmaterial such as steel, aluminum, reinforced plastic material, othermanmade materials, other metals, or combinations thereof. Flange 170 ispreferably annular and shaped to fit against an end of one cylinder101-104 and can be substantially parallel to flange 150. Extension 172can be substantially cylindrical with an inner surface 173 that has alarger diameter that the outer diameter of extension 152. The outersurface can have an annular shoulder 174 for mating with one of theinner surfaces 116 of cylinders 101-104. The shoulder 174 can have anannular surface and be sized to be press fit within any of cylinders101-104. The shoulder 174 engages the inner surface 116 in a pressfitting relationship to prevent the shoulder washer 132 from rotatingrelative to and moving axially relative to the cylinder (hollow portion)in which the shoulder washer 132 is inserted. The shoulder 174 may alsohave a knurled surface to increase the resistance of the shoulder washer132 to rotation and axial movement.

Resilient member 134 can be formed of rubber or other resilient materialcapable of appropriately damping vibrations emanating from engine 14 andtransmitted via plate 20. The resilient member 134 can extend betweenand is preferably attached to flanges 150 and 170. However, it is onlyessential that there be a firm or snug fit between threaded socket 130,shoulder washer 132, and resilient member 134. The amount of materialand the type of material forming member 134 can be selected to achievedesired damping characteristics. For example, the member 134 can have amain section 190 located between flanges 150 and 170, an inner section192, lying adjacent the exterior surface of extension 152 and an outersection 194 lying adjacent the inner surface of extension 172. A gap orhollow space 196 is defined between sections 192 and 194 and can be opento the atmosphere in the direction away from flanges 150 and 170. Gap196 is preferably left open to the atmosphere, but could be filled withan resilient material, if doing so satisfied particular dampingrequirements of the resilient member 134. This gap 196 can permitadditional, less-damped movement in all directions except along thetransverse axis 54. For example, the gap can have a width 197 on eachside of extension 152 corresponding to the desired permitted movement ofthe engine 14 along the longitudinal axis 52. This width 197 may be anydimension but can be in the range of approximately 1.80 mm to 3.50 mm,or preferably about 2.10 mm. Thus, such a width 197 would permit a rangeof movement of the cylinders 101-104 relative to the damping mount 22 inthe direction of the longitudinal axis 52 of the snowmobile or in anydirection in the X-Z plane. The thickness and structural features of theresilient member 134 will determine how much of the vibrations will bedamped. The resilient member 134 can be bonded to both parts and it canbe assembled as one part on the assembly line. One range of the hardnessof a rubber resilient member 134 can be between 60-80 shore A durometer.An example of the rubber material that can be used within resilientmember 134 is black polyurethane, ASTM D2000 M2BG, G21, EF21, F17, Z1,Z2, Z3 or ASTM D2000 M2AA, 817, A13, B33, F17.

Each cylinder 101-104 has two ends where the damping mounts 22 can beplaced. The damping mounts 22 can then be sandwiched between one of thecylinders exterior end and the exterior chassis wall 42 or the interiorsupport wall 44. A fastener such as a bolt 160 is then passed throughthe support wall 42 or 44 of the chassis 12 and then screwed into thethreaded extension 152 of its respective damping mount 22. Thus, theillustrated embodiment will use four bolts 160.

The illustrated embodiment of the invention facilitates the mounting ofthe engine 14 onto the chassis 12 during production in that on theassembly line, workers are standing on each side of the snowmobile 10.If the workers had to attach the engine mount 16 to the chassis 12 fromabove the engine mount 16, it would be cumbersome. With the illustratedengine mount 16, the bolts 160 used to fasten the engine mount 16 to thechassis 12 are inserted laterally, substantially parallel to thetransverse axis 54 making it an easy task to install the engine 14 withthe engine mount 16 attached thereto. The engine mount 16 can beassembled to the bottom of the engine 14 in a sub-assembly productionline.

Ideally with engine mount 16, 100% of the vibrations can be absorbed andat the same time, have a non-adjustable engine mount 16 that would keepthe pulleys 86 and 88 in perfect alignment. In other words, in order toachieve the best alignment of the engine 14 with respect to the chassis12, a rigid attachment between the engine 14 and the chassis 12 isdesired. One important aspect of the alignment of the engine 14 is thelife of the drive belt 90. The life of the drive belt 90 can be effectedby the alignment of the engine 14 with respect to the chassis 12. If theengine 14 moves laterally, that is, along the transverse (Y-) axis 54,or rotates around the height (Z-) axis, then the transmission that canbe attached to the engine 14 and the driven pulley 88, which may befixed the chassis 12, will become misaligned. Such misalignment mayreduce the belt life.

To obtain a certain comfort level for the driver and maintain the bestalignment between the driving pulley 86 and the driven pulley 88, engine14 must be equipped with dampers that achieve both good vibrationdamping yet also maintain good alignment. The engine base plate 20 anddamping mounts 22 cooperate to ensure that desired amounts of vibrationfrom the engine can be absorbed and at the same time suitably limit themovement of the engine 14 and maintain the desired amount of alignmentof engine 14.

The one damping mount 22 can be placed at each end of the cylinders101-104 so that any movement of the engine along the longitudinal (X-)axis 52, the height (Z-) axis, or in the X-Z plane, places the resilientmember 134 in a shear force situation. Such longitudinal (X-) axis,Z-axis 55, or X-Z plane movement of the engine 14 along the longitudinalaxis 52 is not as significant a concern since the pulleys 86 and 88 willadjust to this change and such movement will not affect the life of thebelt 90 as movement along the transverse axis 54. Any lateral movementalong the transverse (Y-) axis 54 or rotation around the Z-axis 55 willresult in the resilient members 134 undergoing compression or tension.The alignment of the pulleys 86, 88 is very important in considering thelife of the belt 90 and the life depends mainly on the lateral movementalong the transverse axis 54 and rotation around the Z-axis 55. Also,those movements of the engine 14 can correspond to the same movement ofthe transmission and the pulley 86. When the engine 14 experiences suchmovement, it is advantageous to have resilient members 134 incompression since compression offers much more support than when theresilient members 134 are in a shear situation. In the conventionalengine mounts, the rubber was partially in shear when the engine wassubjected to a lateral force.

The thickness of the resilient member 134 along the transverse axis 54,between flanges 150 and 170 and thus the damping ability of the member134 can be determined through testing. An acceptable thickness ofresilient member 134 between flanges 150 and 170 can be between 8 mm and12 mm. However, any acceptable thickness range is dependent on amount ofvibration to be damped. The resilient material 134 can be bonded to thesocket 130 and the washer 132 wherever it is in contact with the matingparts 130 and 132. Such bonding enables the resilient material in member134 to work in shear as well as in tension. The axis of the dampingmount 22 and its elements will be in the lateral (y-axis) direction,parallel to the transverse axis 54 of the engine 14. Therefore, anymovement of the engine 14 along the transverse (Y-) axis 54 would putthe resilient material of the member 134 in compression or tension onthe opposite direction. Any movement in the X-Z plane, upward ordownward movement along the height (Z-) axis or forward or rearwardmovement along the longitudinal axis 52 will place the resilient member134 in shear since it is bonded to the socket 130 and the washer 132.

One aspect of the damping mount 22 is the amount of movement it willallow in the X-Z plane through the use of gap 196. The movement allowedbetween the shoulder washer 132 and the threaded socket 130 by gap 196can be very small, for example, approximately 2.10 mm. This can provideenough movement to absorb the vibration of the engine 14 itself but notenough to let any outside forces, such as hard bumps from the trail,move the engine 14 more than desired. Vibration from the engine 14 couldsufficiently be damped with a thickness of the resilient member 134 asdetermined, as through testing. Any movement between the shoulder washer132 and the threaded socket 130 of more than the desired amount, forexample, 2.20 mm will place those two parts 132, 130 in contact and thenlimit additional movement.

Another advantage of the damping mount 22 is the size of the matingsurface area that exists between the surface 154 of flange 150 and thesidewall 42 of the chassis 12. With the large flange 150 on the end ofthe threaded socket 130, a large contact area is formed between thedamping mount 22 and the side wall 42 of the chassis 12 to form a moresecure and rigid connection between the parts over a large surface area.For example, the flange 150 can have an outermost diameter ofapproximately 36-38 mm.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments and elements, but, to the contrary, is intended tocover various modifications, combinations of features, equivalentarrangements, and equivalent elements included within the spirit andscope of the appended claims. Furthermore, the dimensions of features ofvarious components that may appear on the drawings are not meant to belimiting, and the size of the components therein can vary from the sizethat may be portrayed in the figures herein.

What is claimed is:
 1. A method of assembling a vehicle, includingproviding a chassis having a longitudinal axis, a transverse axis, atop, a bottom, and a side; providing an engine; providing a base plateincluding a first attaching portion; fastening the engine to the baseplate; positioning the engine and the base plate within an upwardlyopening recess in the chassis; and inserting a fastener through the sideof the chassis and into the first attaching portion of the base plate ina direction that is substantially parallel to the transverse axis.
 2. Amethod according to claim 1, wherein securing of the engine to the baseplate occurs prior to the positioning of the engine within the upwardlyopening recess in the chassis.
 3. A method according to claim 2, whereinthe step of inserting a fastener through the side of the chassis andinto the first attaching portion of the base plate in a direction thatis substantially parallel to the transverse axis further comprisesinserting a resilient mounting element within the first attachingportion.
 4. A method according to claim 3, wherein movement of theengine parallel to the transverse axis places the resilient member incompression.